Kenny Cooper scored on a free kick early in the second half after Jeff Cunningham had been fouled by Rapids defender Stephen Keel at the edge of the penalty area. Cooper curled a 20-yard shot over the defensive wall and past keeper Matt Pickens in the 57th minute.
Colorado missed a chance to tie the score five minutes later. Kwame Sarkodie's pass went to Greg Dalby inside the Dallas penalty box, and Dalby's point-blank shot caromed off FCD goalie Ray Burse, who had replaced starter Dario Sala at halftime.
Burse stymied Colorado again with a double-save five minutes from the final whistle. He dove to turn away a Sarkodie shot and bounced up quickly to smother a follow-up effort from Jordan Harvey.
In its other preseason matches against MLS opposition, FCD played a scoreless tie with Houston and lost to the Dynamo, 3-0, as the teams played a home-and-home series before they left Texas.
Head coach Schellas Hyndman has given Marcelo Saragosa, normally a holding midfielder, praise for his performances while being tested at right back, while Adrian Serioux continues his recovery from multiple injuries. Former Crew and RSL defender Daniel Torres, who rejoined MLS after a year and a half playing in Scandinavia, is getting a lot of minutes at left back.
"I can give this team the experience that I gained from playing in Europe," Torres said. "I learned so many great things, especially last year when I was in Norway and with good coaches. That gives me confidence and a little something extra to give to this team."
Dallas will play Florida International University and Swedish team BK Hacken before returning to Dallas on Saturday. Midfielder Andre Rocha has joined the team after being stuck in Brazil awaiting the renewal of his work visa. He led FCD with eight assists last year.
Feb. 17 in Sunrise, Fla.
FC Dallas 1 Colorado Rapids 0. Goal: Cooper 57
FC Dallas -- Sala (Burse, 46), Wagner (Torres, 60), Purdy, Moor (Pitchkolan, 65), Saragosa (Wallace, 70), van den Bergh (Shea, 70), Ricchetti, McCarty (Rocha, 70), Avila (Guarda, 46) (*Guerra, 75), Cunningham (Bucknor, 60), Cooper (Marosevic, 60).